* Arabtec falls 10% in Dubai * Saudi drops on banking, petrochemical shares * First Abu Dhabi Bank gains in Abu Dhabi * Qatar’s Mesaieed extends gains on MSCI inclusion May 19 (Reuters) – Dubai’s stock market closed down on Sunday, dragged lower by property and banking shares as Gulf markets ended the day mixed amid rising geopolitical tensions that have shaken investor confidence. Dubai’s main index fell 2.2%, led by a 3.1% decline in heavyweight Emaar Properties and a 2.3% drop in bank Emirates NBD. Dubai Islamic Bank fell 1.6%. DAMAC Properties, which on May 15 reported its smallest profit since going public in 2015, shed 3.0%, recovering some earlier losses. Arabtec Construction shares closed at a limit down of 10% after it